There's many wonderful writing apps for the iPad.If you have a Mac and are willing to spend around 10$ bucks total, I recommend iA Writer. iA Writer syncs with iCloud and the app is available for both iOS and Mac.

Evernote is a great app too, but if you're going to write as much as it looks like you will, you will end up paying for a subscription (which isn't bad - but over that I'd recommend iA Writer).